Power generation facilities such as wind power plants comprised of one or more wind-turbine generators, gas-turbine plants, steam-turbine plants and the like have auxiliary electrical loads such as pumps, motors, HVAC equipment, lighting, and other balance of plant (BOP) equipment that are supplied power from one or more auxiliary busses within the facility. These auxiliary busses can be alternating current (AC) electrical busses and direct current (DC) electrical busses where the AC is converted to DC and used to supply DC loads. In some instances, these busses experience overvoltage conditions that can be caused by, for example, sudden tripping of one or more of the generators at the power generation facility. Generally, these overvoltage conditions are short in duration (e.g., lasting 1 second or less), but if not mitigated, these overvoltages may damage the BOP equipment connected to the busses.
Accordingly, described herein are systems and methods of limiting voltage on auxiliary busses during an overvoltage event.